Vernier Isolastic adjustment

Hi All, I am just setting my isolastics,
This site says 0.010" clearance front and rear, but the manual says back off by 1 1/2 holes to give the correct 0.060" .
See manual section F15 clause 15. Am I missing something or is a typo error ?
Thanks
Staytite

In my 850 Mk3 manual copy, it reads 0.006 in = six thou. not 0.060"

I suggest you still check the gap manually with feelers as the: "Back off the adjuster by 1.1/2 holes" method isn't very accurate as clearance often reduces when the Iso. bolt/stud is tightened.

Hi LAB

You are entirely correct = 0.006"

I will check with feelers

But which is correct 0.006 or 0.010*?

Thanks
Staytite

Staytite said:

But which is correct 0.006 or 0.010*?

Click to expand...

Setting tighter clearances (not less than 0.005") gives better handling but can increase vibration. Increasing the clearance reduces vibes but handling can suffer, so the clearance can be a matter of preference.

Hi LAB

Just read in the INOC Tech Digest minimum is 0.010" so aim for 0.10 to 0.015"!!!

Staytite

Staytite said:

Just read in the INOC Tech Digest minimum is 0.010" so aim for 0.10 to 0.015"!!!

Click to expand...

0.010"?

Well, the 850 Mk3 manual recommends 0.006" and personally, I don't run mine over 0.010".

(Pre-Mk3 manual states: "Ideal clearance 0.010")

When are you guys going to switch to a metric system ?

Click to expand...

You cant use a metric measurement as these are 'Imperial' verniers! :lol:

Iso clearance is a contentious subject but here goes. Put away your feeler gages and set your isos by trial and success. Last summer I set my iso clearances without measuring, just kept opening up the clearance front and rear in 1/4 turn increments until the bike smoothed out on a test drive. Only took a few tries. I started by screwing in the adjustable mounts tight as a starting point, then back off say 1/4 turn. The idea is to run them as loose as possible while making sure there's no clunk in the iso and no rear wheel play(as opposed to the rubbery give of the iso mount) when the rear wheel is pushed/pulled with bike on centerstand. If the rear wheel has maybe 1/8" of rubber damped motion but no slack your handling will be good. My 75 Mk3 runs smoother since I set the isos this way than it did during my previous 22 years of ownership trying to measure/set clearances. Try it. You have nothing to lose but vibration.

If you measured the results front and rear when you finished, would you mind sharing?

Dave
69S

Yes, measurements from the "feel" experiment would be cool.

I have not ridden mine but I just put vernier (Andover) Isolastics on my '74 and set them for a tight-feeling .010".

I like it real smooth so I have mine set at about 20 thousandths front and 15 in the rear.

I don't push it hard enough through corners to need the rear tightened up any more than that.

I don't know where I got this, but it works for me -

After setting the vernier at the 1-1/2 holes, start up the bike.

If you've got more vibration than you like up to 3000 RPM, the rear is tight and the front is OK

3000-5000 RPM, front is tight and rear is OK

too much vibration throughout the range, both are too tight.

Move the verniers in 1/2 hole increments until you're happy.

Of course, if its smooth at 1-1/2 holes, you can also try tightening a little until you've reached your personal 'sweet spot'

Well, once I get the bike back together and can fire it up, I will give that a try. I know where I've set it, and I'd be interested to see where I end up. The bike was mighty smooth before I took it apart and removed the factory-original Isolastic rubbers. They were actually in pretty good shape but had definitely settled off-center. I didn't think to measure the clearance before I took it apart, but as I recall it was more than .010" quite a number of years ago. Anyway, I will give your technique a try. Hoping to get it on the road again this weekend. Got one of those link-type head steadies, too. Hoping for glorious handling and a smooth ride...
Mark